1. Field of the Invention
The present invention relates to detergents based on nonionic surfactants containing a combination of a polyvinyl pyrrolidone polymeric constituent and a cationic compound which counteract the transfer of dyes and brighteners from colored or brightened fabrics to white, light-colored or non-brightened fabrics when such fabrics are laundered together.
2. Description of Related Art
The transfer of dyes and brighteners that occurs when washing mixed loads of colored and white fabrics or colored and light-colored fabrics is a well-known problem to which several solutions have already been proposed. Unfortunately, none of these solutions has been entirely satisfactory, either because the cleaning agents have only a limited effect on a large number of dyes and fabrics in use today or because the agents only counteract the transfer of either the dye or the brightener, but not both.
Great Britain Patent No. 1,348,212 describes a built detergent having a discoloration-inhibiting additive consisting of a homopolymer or copolymer of polyvinyl pyrrolidone. According to the teachings of this patent, the detergent contains a nonionic surfactant and from about 5 to about 40% by weight of the partially or completely water-soluble homopolymer of vinyl pyrrolidone or a copolymer of vinyl pyrrolidone and a suitable monomer, based on the weight of nonionic surfactant and vinyl pyrrolidone polymer.
German Patent Application No. 29 16 656 describes detergents containing alkylpyridinium salts for preventing transfer of optical brighteners from brightener-containing fabrics to brightener-free fabrics during the washing process. The detergents contain from 0.5 to 10% by weight of the alkylpyridinium salt, based on the detergent as a whole.
It is also known from German Patent Application No. 12 24 698 that fabrics, discolored because of the transfer of brighteners, can be treated with a solution of tertiary, quaternary or branched-chain organic nitrogen bases, or salts thereof, to regenerate their color.